Decoder device and receiver using the same

ABSTRACT

An object of the present application is to provide the display of motion picture data used in both of analog and digital broadcasts with high picture quality and a common user interface. The above object can be achieved by providing a plurality of picture format converters, a plurality of OSD circuits, and means for storing motion picture data used in an analog broadcast in a common memory.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a digital datatransmitting/receiving system for transmitting motion image or picturedata coded by the International Standard of ISO/IEC, MPEG-2 or the likefor coding motion picture data with high efficiency. The presentinvention also relates to a digital data decoder device for decodingcoded motion picture data and outputting it therefrom and a receiver forreceiving displayed digital data. Incidentally, a description will bemade below of an example in which the present invention is applied to adigital broadcast. However, the present invention is not necessarilylimited to this. The present invention can be also applied to an examplerelated to the transmission and reception of data such as datacommunications or the like in a similar mechanism.

[0003] 2. Description of the Related Art

[0004] Due to an increase in the amount of digital motion image orpicture data, high-efficiency coding means performs compression thereonto eliminate redundancy or the like and thereafter transmits or recordsthe coded motion picture data, whereby the cost of transmission orrecording can be reduced. As the high-efficiency coding means, there iswell known an MPEG-2 system standardized by ISO/IEC/JTC1/SC29/WG11.

[0005] As to the coding based on the MPEG-2 system, respective frames ofmotion picture data are separated into an I frame (Intra Picture) codedwithout having a frame (reference frame) referred as a predicted value,a P frame (Predictive Picture) with only frames lying in the forwarddirection in display order as reference frames, and a B frame(Bidirectional Picture) with each frame lying in the forward directionand each frame lying in the backward direction as reference frames. Uponactual coding, two reference frames lying in the forward and backwarddirections are required to exist upon decoding the B frame, and the datacoding is performed after the sequence of frames is skillfullyinterchanged.

[0006] While a decoder device successively decodes coded motion picturedata transmitted in coding order, it is necessary to temporarily storethe decoded data in a memory and re-arrange or sort the same inaccordance with display order. It is also necessary to use decoded dataof the I and P frames as reference data upon the subsequent decoding ofB frame. The memory is required to certainly store motion picture datacorresponding to two frames therein. The re-arrangement or sorting ofthe data in frame order is performed using each memory corresponding tothe two frames. Since the data is coded in one frame unit, the framedata cannot be displayed simultaneously with decoding even in the caseof the B frame when one frame is made up of two interlaced fields as inthe case of a television signal. It is necessary to convert the framedata to field data sorted in the order of scanning lines. Even for thispurpose, a memory corresponding to about one frame is required.

[0007] Further, image or picture signals compressed by the MPEG-2 systemare classified into several categories. Special emphasis is placed onthe two categories called a “main level (ML)” and a “high level (HL)” inparticular from an application standpoint.

[0008] The main level corresponds to the NTSC system of horizontal 720pixels×vertical 480 scanning lines×frame frequency of 30 Hz and isadopted for a satellite digital broadcast. The high level corresponds toa high-definition image or picture expressed in horizontal 1920pixels×vertical 1080 scanning lines×frame frequency of 30 Hz. It hasbeen determined to be adopted for a US ground wave digital broadcastintended to provide high picture-quality broadcasting services. The USground wave digital broadcast has been introduced in the May 1997 issue,pp 47-53 of Nikkei Microdevice, for example.

[0009] The capacity of a memory required to decode the coded motionpicture data based on the MPEG-2 system is equivalent to one added withthat for a coded image or pictorial data buffer for temporarily storinga coded image upon decoding in addition to the capacity corresponding tothe three frames. The capacity of the coded image data buffer (VBV)corresponds to 1,835,008 bits in main level and 9,781,248 bits in highlevel. Even in the case of combinations of coding devices and decoderdevices different in manufacturer, this capacitive value is determinedby the MPEG-2 system as the required minimum capacity necessary toalways maintain the assurance of suitable coding/decoding.

[0010] As also introduced in the May 1997 issue, pp 47-53 of NikkeiMicrodevice, the picture formats of the coded motion picture data rangeover many divergences. Thus, the display of decoded motion picture datacorresponding to these all picture formats on a specific monitor needsto use a display device capable of displaying all these picture formatsor utilize a format converting device between a decoder device and adisplay. The latter is advantageous to reduce the cost of the monitor.

[0011] Further, the satellite digital broadcast and the ground wavedigital broadcast are not independent services for users who receivethese broadcasts and enjoy the same. It is very natural that there is ademand that the users desire to enjoy even the conventional analogbroadcast through the same television receiver. It is necessary to meetthis demand.

SUMMARY OF THE INVENTION

[0012] An example of a device for decoding coded motion picture data,which can be used in a receiver for broadcast service in which pictureformats of coded motion picture data have a variety of picture sizes asin the US ground wave digital broadcast, has been disclosed in JapanesePatent Application Laid-Open No. Hei 8-205161. This example is aproposal wherein a high-definition motion picture (HD:High Definition)is decoded while being downsampled to a standard motion picture (SD:Standard Definition) corresponding to the same format as the analogbroadcast, thereby facilitating provisions to a plurality of pictureformats.

[0013] However, the present example has a problem in that thehigh-definition picture data is merely outputted as the standard picturedata and hence the users cannot enjoy a precious high picture-qualitybroadcast. Further, the example also contains no mentions of aconfiguration capable of receiving the analog broadcast simultaneously.

[0014] An object of the present invention is to solve the aboveproblems, facilitate provisions to broadcasted variety of pictureformats and realize simultaneous reception of an analog broadcast.

[0015] According to one aspect of the invention, for achieving the aboveobject, the present invention comprises means for decoding motionpicture data used in a digital broadcast, memory means for storing thedecoded motion picture data therein, first on-screen data multiplexingmeans for mixing the decoded motion picture data with first on-screendata, first picture format converting means for converting the firston-screen data-mixed motion picture data into format form, and secondon-screen data multiplexing means for mixing the format-converted motionpicture data with second graphics data, whereby the second on-screendata-mixed motion picture data is outputted. Thus, the motion picturedata used in the digital broadcast can be outputted in an arbitrarypicture format so that a high picture-quality display can be done. Theon-screen data allows the high picture-quality display too. Further, thepresent invention includes second picture format converting means. Theoutput of second format-converted motion picture data as an output for arecording device from the second picture format converting means makesit possible to use the conventional analog broadcasting recording device

[0016] Further, the present invention includes picture data capturingmeans for inputting motion picture data used in an analog broadcasttherein, and motion picture data memory storing means for allowing thememory means to store the motion picture data used in the analogbroadcast. By applying the first picture format converting means even tothe motion picture data used in the analog broadcast, the motion picturedata can be outputted or displayed without drawing a distinction betweenthe analog broadcast and the digital broadcast.

[0017] According to the present invention, as has been described above,high-definition motion picture data can be displayed while remaininghigh in image quality as the high-definition motion picture data.Further, even if the data is broadcasted in the form of a plurality ofimage or picture formats, their display picture formats are converted tothe same. It is therefore possible to achieve a reduction in the cost ofa monitoring device. Since standard motion picture data can be outputtedsimultaneously with the display motion picture data in addition to thedisplay motion picture data, the conventional analog broadcastingrecording device can be also utilized. Further, since the conventionalanalog broadcast can be also converted to a high-definition motionpicture format and displayed in this form, even the conventional analogbroadcast can be displayed with high picture quality, describedspecifically, an easy-to-see screen from which scanning lineinterference like line flicker (corresponding to such a phenomenon thatfine points are flickering) can be provided. Moreover, since data can bedisplayed in picture-in-picture form or graphics data can be on-screendisplayed, a table for an electronic program guide can be displayed.According to the electronic program guide, a cursor of a remotecontroller is set to or aligned with a program to thereby make itpossible to choose a channel and make a recording reservation. Theprovision of two-system OSDs allows graphics to be displayed on TV butunrecorded on VTR as well as superimposition of graphics on both the TVdisplay and VTR recording, thus making it possible to implement aneasy-to-understand user interface.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] These and other features, objects and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings wherein:

[0019]FIG. 1 shows a first embodiment of the present invention and is ablock diagram illustrating the present invention applied to a digitalbroadcasting receiver;

[0020]FIG. 2 is a block diagram depicting a reformatter for convertingan image format into reformatted form;

[0021]FIG. 3 is a diagram for describing operation modes of thereformatter employed in the first embodiment;

[0022]FIG. 4 shows a second embodiment of the present invention and is ablock diagram showing the present invention applied to a digitalbroadcasting receiver;

[0023]FIG. 5 is a diagram for explaining operation modes of areformatter employed in the second embodiment;

[0024]FIG. 6 shows a third embodiment of the present invention and is ablock diagram illustrating the present invention applied to a digitalbroadcasting receiver;

[0025]FIG. 7 shows a fourth embodiment of the present invention and is ablock diagram illustrating the present invention applied to a digitalbroadcasting receiver;

[0026]FIG. 8 is a block diagram illustrating an NTSC decoder and aninput processor;

[0027]FIG. 9 depicts a fifth embodiment of the present invention and isa block diagram illustrating the present invention applied to a digitalbroadcasting receiver;

[0028]FIG. 10 illustrates a sixth embodiment of the present inventionand is a block diagram showing the present invention applied to adigital broadcasting receiver;

[0029]FIG. 11 show s a seventh embodiment of the present invention andis a block diagram illustrating the present invention applied to adigital broadcasting receiver;

[0030]FIG. 12 illustrates a modification of the first embodiment of thepresent invention and is a block diagram illustrating the presentinvention applied to a digital broadcasting receiver;

[0031]FIG. 13 depicts another modification of the first embodiment ofthe present invention and is a block diagram illustrating the presentinvention applied to a digital broadcasting receiver;

[0032]FIG. 14 shows a modification of the fourth embodiment of thepresent invention and is a block diagram illustrating the presentinvention applied to a digital broadcasting receiver;

[0033]FIG. 15 illustrates another modification of the fourth embodimentof the present invention and is a block diagram illustrating the presentinvention applied to a digital broadcasting receiver;

[0034]FIG. 16 depicts a modification of the fifth embodiment of thepresent invention and is a block diagram illustrating the presentinvention applied to a digital broadcasting receiver; and

[0035]FIG. 17 show s another modification of the fifth embodiment of thepresent invention and is a block diagram illustrating the presentinvention applied to a digital broadcasting receiver.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0036] Preferred embodiments of the present invention will hereinafterbe described with reference to the accompanying drawings.

[0037]FIG. 1 shows a first embodiment of the present invention and is ablock diagram illustrating the present invention applied to a digitalbroadcasting receiver. In FIG. 1, reference numerals 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 and 23indicate a digital broadcasting antenna, a digital broadcasting tuner, afront/end circuit, a descrambler, a transport demultiplexer, a clockgenerator, a system controller, a memory, a memory interface, a memorybus, a video header parser, a video decoder, a first on-screen displaycircuit (hereinafter described as “OSD circuit”), a reformatter, asecond OSD circuit, a first digital-analog converter (hereinafterdescribed as “DAC”), a monitor driving circuit, a monitor, an audioheader parser, an audio decoder, a second DAC, a speaker drivingcircuit, and a speaker, respectively.

[0038] A broadcasting wave is received by the digital broadcastingantenna 1 and thereafter converted into frequency form by the digitalbroadcasting tuner 2. The front/end circuit 3 demodulates a8-PSK-modulated received signal, for example and corrects itstransmission error using error correction parity so as to output atransport stream. With respect to the transport stream, principaldigital data thereof is scrambled in a pay broadcast. The scrambled datais descrambled by the descrambler 4 with key information outputted fromthe system controller 7 as an auxiliary input (where detailedconnections around the system controller 7 are omitted because thedrawing is put out of order). Further, several programs having differentcontents are generally contained in the transport stream in multiplexedform. The transport demultiplexer 5 receives instructions for eachdesired user's program through the system controller 7 to separate oneprogram from the plurality of programs and further separate it intocoded video data and coded audio data constituting coded motion image orpicture data. The separated respective code data are temporarily storedin a dedicated area of the memory 8 through the memory bus 10 and thememory interface 9. Further, the transport demultiplexer 5simultaneously separates the multiplexed key information, programmultiplex table information representing how to multiplex the respectiveprograms, etc. other than the motion picture data from the inputformation or stream and transmits the separated information to thesystem controller 7. Their transmission is performed before theseparation and selection of one program.

[0039] Moreover, the transport multiplexer 5 extracts time informationfrom the transport stream and sends it to the clock generator 6. Theclock generator 6 controls an internal timer so that the time of adecoder device is set identical to that on the transmitting side, andgenerates a clock signal used within the decoder device in synchronismwith information from the corresponding timer. In the drawing, lines fordistributing the clock signal are omitted to avoid the cumbersomeness oftheir description.

[0040] The coded video data stored in the memory 8 is read from thememory 8. The video header parser 11 obtains format information such asan image or pictorial size or the like as header information from theread data and transmits the format information to the video decoder 12and the system controller 7. Further, the video header parser 11extracts title data about a closed caption or the like, for examplerelated to the contents of the coded video data and sends it to thesystem controller 7. While the video decoder 12 decodes the coded videodata in accordance with the extracted image or picture formatinformation, it writes the decoded image or pictorial data into apredetermined frame memory area of the memory 8 through the memory bus10 and the memory interface 9 in its decoding process. As describedabove, the frame memory area corresponds to three frames, and I an Ppictures are read as image or pictorial data in a reference frame upondecoding P and B pictures. These decode operations are normally producedas pictorial data in a frame comprised of a combination of two fields,whereas the video decoder 12 reads and outputs the pictorial data fromthe frame memory area of the memory in order of scanning lines everyfields per display frames while being re-arranged or sorted in order ofthe display frames.

[0041] The first OSD circuit 13 mixes on-screen data into the outputpictorial data of the video decoder 12. The mixed on-screen datacorresponds to data processed for display from the above-described titledata about the closed caption by the system controller 7. The dataprocessed for display is stored in the memory 8 before it is sent to thefirst OSD circuit 13 in advance. Each time the first OSD circuit 13requires data in accordance with the output pictorial data, theprocessed data is supplied via the memory interface 9 and the memory bus10 to the first OSD circuit 13 where the output pictorial data and theonscreen data are mixed together in synchronism with each other.Further, the mixed pictorial data is supplied to the reformatter 14.

[0042]FIG. 2 is a block diagram of the reformatter 14 for converting animage or picture format into reformatted form. In FIG. 2, referencenumerals 141, 142, 143 and 144 indicate selectors which select andoutput any of three inputs A, B and C, respectively. Reference numeral145 indicates a memory controller, reference numeral 146 indicates ahorizontal size converter, and reference numeral 147 indicates avertical size converter, respectively. The selectors designated atreference numerals 141 through 144 control the selection of any input ofA, B and C by the system controller 7 according to the ratio between animage size of the coded video data and an image size displayed on themonitor 18 to be described later.

[0043]FIG. 3 is a diagram for describing operation modes of thereformatter 14. Horizontal 1920 pixels (effective component), vertical1080 lines (effective component), a frame frequency 30 Hz, 2:1 interlacescanning and a screen aspect ratio 16:9, which are well known as ahigh-definition image (HDTV), are assumed as formats of image datadisplayed on the monitor 18. Size conversion coefficients of thehorizontal size converter 146 and the vertical size converter 147 andwhich input would be selected by the four selectors, are shown in thedrawing. When, for example, an image size inputted to the reformatter14, corresponding to the output of the first OSD circuit 13 has aprogressive format expressed in horizontal 1280 pixels×vertical 720scanning lines at the third stage from above in FIG. 3, the screenaspect ratio of 16:9 and a frame frequency of 60 Hz, the number ofpixels is converted from 1280 pixels to 1920 pixels with a horizontalsize conversion ratio as (3/2) times, and the number of scanning linesis converted from 720 scanning lines to 1080/2 scanning lines with avertical size conversion ratio as (3/4) times. In order to convertprogressive to interlace, frames of 60 Hz are caused to correspond tofields respectively and thereby the phases of scanning lines in twofields are made different from each other.

[0044] The reformatter 14 has a memory controller 145 and utilizes thememory 8 through the memory bus 10 or the like to output theformat-converted pictorial data at a predetermined data rate. Theselectors 141 through 144 are provided so as to minimize the usagecapacity of the memory 8 and a data band width of the memory bus 10.That is, when the conversion ratios of the horizontal size converter 146and the vertical size converter 147 are smaller than 1, the selectors141 through 144 are controlled so that the horizontal size converter 146and the vertical size converter 147 are placed before the memorycontroller 145, whereas when they are greater than 1, the selectors 141through 144 are controlled so that they are placed after the memorycontroller 145.

[0045] Since the vertical size conversion coefficient is smaller than 1in the above-described embodiment, the selector 143 selects A and inputsinput pictorial data to the vertical size converter 147. The selector141 selects C so that the output of the vertical size converter 147 isset as an input to the memory controller 145, after which it is writteninto the memory 8. Thereafter, the pictorial data is read along apredetermined rate from the memory 8. While the pictorial data read fromthe memory 8 is outputted from the memory controller 145, it is set asan input to the horizontal size converter 146 by allowing the selector142 to select B. The reason why the horizontal size converter 146 isplaced after the memory controller, is that the size conversion ratio islarger than 1. If both the size conversion ratios are greater than 1,then the vertical size converter 147 and the horizontal size converter146 are both placed after the memory controller 145. However, thevertical size converter 147 is placed in front of the horizontal sizeconverter 146. This is because this placement is effective in reducingthe size of a line buffer (not shown) provided in the vertical sizeconverter 147. When both the size conversion ratios are smaller than 1and both the vertical size converter 147 and the horizontal sizeconverter 146 are placed before the memory controller 145 due to thesimilar reason, the horizontal size converter 146 is provided so as toprecede the vertical size converter 147. Returning to the illustratedcase, the selector 144 finally selects the output (B) of the horizontalsize converter 146 and sets it as the output of the reformatter 14.

[0046] Referring back to FIG. 1, a further description will be madecontinuously. The output of the reformatter 14 is inputted to the secondOSD circuit 15. The second OSD circuit 15 mixes graphics data such as aprogram guide or the like into the input pictorial data. The output ofthe second OSD circuit 15, which has been mixed with the graphics data,is converted to an analog signal by the first DAC 16, followed bydisplay on the screen of the monitor 18 through the monitor drivingcircuit 17.

[0047] The graphics data mixed by the second OSD circuit 15 is producedby the system controller 7 and is stored in the memory 8 in advance,from which the second OSD circuit 15 reads it based on instructionsgiven from the system controller 7. With respect to the contents of aprogram guide, for example, the demultiplexer 5 font-converts charactercodes into graphics data along the program multiplex table informationseparated from the transport stream, after which it is produced by beingmixed with background graphics. The graphics data mixed by the secondOSD circuit 15 is based upon the image or picture-format of the outputof the reformatter 14 but is not based on the picture format of thecoded video data decoded by the video decoder 12. Therefore, thegraphics data such as the characters or the like is thereafter displayedon the monitor 18 without being subjected to significant processing. Thegraphics data excellent in image or picture quality can be displayedthereon. The program guide is used when a user selects a program. Theability to display the character graphics data high in picture qualityleads to high quality of a user interface.

[0048] The coded audio data is read from the memory 8 by the audioheader parser 19. The audio header parser 19 specifies a coding systemand detects synchronous information from the coded audio data to therebyextract audio parameters such as a sampling frequency, etc. and notifiesthe same to the audio decoder 20. The audio decoder 20 decodes the codedaudio data using these audio parameters to thereby obtain audio data.The decoded audio data is converted to an analog audio signal by thesecond DAC 21, after which the analog audio signal is outputted from thespeaker 23 through the speaker driving circuit 22.

[0049] According to the embodiment as described above, the suitablesetting of the operation of the reformatter 14 based on the pictureformat of the coded video data allows the conversion of a plurality ofimage or picture formats to one picture format and display thereof onthe monitor 18. This can simplify a scan deflection circuit (not shown)of the monitor 18 and is useful for a reduction in the cost of theentire receiver. When the decoder device (corresponding to the antenna 1to the first and second DACs 16 and 21) for the coded motion picturedata, and the monitor driving circuit 17, the monitor 18, and thespeaker driving circuit 22 and the speaker 23 are provided as separatedevices, the conventional analog broadcasting receiver can be also usedas a monitor device by setting the output of the decoder device for thecoded motion picture data to the same picture format as that for thepresent-existing analog broadcast.

[0050] In the present embodiment as well, the two OSD circuits (13 and15) are provided. Thus, program inherent information suitable fordisplaying the broadcasted coded video data in the form of the pictureformat and on-screen display information for improving the userinterface can be multiplexed into separately-decoded image data. This isalso useful in displaying the data on the monitor 18 in one pictureformat.

[0051] A second embodiment of the present invention will next bedescribed with reference to FIG. 4. However, components shown in FIG. 4identified by the same reference numerals as those in FIG. 1 havealready been described and only the difference between FIG. 4 and FIG. 1will therefore be explained.

[0052] In FIG. 4, a second reformatter 24, a third DAC 25, arecording-output circuit 26 and a recording device 27 are added to thefirst embodiment shown in FIG. 1.

[0053] The output pictorial data of the first OSD circuit 13 is suppliedeven to the second reformatter 24 as well as to the reformatter 14(hereinafter described as a first reformatter). The second reformatter24 is also identical to the first reformatter described using FIG. 2 inconfiguration. The second reformatter converts a picture format of theoutput thereof to the same SDTV as an analog broadcast regardless of thepicture format of the coded video data and outputs it to a recordingmedium such as a video tape through the DAC. Alternatively, the secondreformatter converts the picture format of the output thereof to thesame HDTV as a digital broadcast regardless of the picture format of thecoded video data and outputs it to a recording medium such as a DVD, aD-VHS or the like without having to use the DAC. The present embodimenttakes a configuration in which a monitor 18 and the recording device 27are both provided in FIG. 4. However, the present embodiment may take aconfiguration of a built-in VTR in which the driving circuit 17 and themonitor 18 shown in FIG. 1 are replaced by the output circuit 26 and therecording device 27. Alternatively, the present embodiment may take aconfiguration of a built-in DVD in which the DAC 16, driving circuit 17and monitor 18 shown in FIG. 1 are replaced with the output circuit 26and the recording device 27. These drawings are shown in FIGS. 12 and 13respectively. While the reformatters are shown in separate blockdiagrams as illustrated in the respective drawings, the first and secondreformatters may be commonly used as one reformatter.

[0054]FIG. 5 is a diagram showing size conversion ratios used to obtainan SDTV output by the second reformatter 24 and settings of selectors141 through 144 with respect to various input image or picture formats.Further, the output of the second reformatter 24 is used to performrecording to the recording device 27 through the third DAC 25 and therecording output circuit 26. Incidentally, the recording device 27 maybe constructed as the same device as the decoder device and receiveraccording to the present invention. It is however needless to say thatit may be provided as a separate device.

[0055] The present embodiment is characterized in that the secondreformatter 24 is provided to obtain recording image data with a viewtoward recording it on a recording medium such as a video tape, a DVD, aD-VHS. Particularly when the output picture format of the secondreformatter 24 is set to SDTV, an inexpensive VTR like the alreadywidely-available VHS system can be used. On the other hand, when theoutput picture format is set to HDTV, the DVD and D-VHS considered to bewidely available from now on can be used.

[0056] A third embodiment of the present invention will next bedescribed with reference to FIG. 6. Even in the description of thepresent embodiment, the description of certain elements common to thoseshown in the already-described embodiments will be omitted.

[0057] In FIG. 6, a down mixer 28 and a fourth DAC 29 are added to thesecond embodiment shown in FIG. 4. The down mixer 28 is used to down-mix2CH or monophonic audio data with, for example, 3/2-mode multichannelaudio data decoded by an audio decoder 20. The audio header parser 19extracts the most suitable downmixed parameters from coded audio dataand performs downmixing in accordance with the same. The downmixed audiodata is transmitted to the recording output circuit 26 through thefourth DAC 29 and recorded by a recording device 27 together with avideo signal.

[0058] In the present embodiment, the downmixed parameters instructed onthe broadcasting station side can be reflected faithfully so that highsound-quality recording can be done.

[0059] As a modification of the, present embodiment, the downmixed audiosignal corresponding to each of the outputs of the down mixer 28 and thefourth DAC 29 may be constructed so as to be supplied to the speakerdriving circuits 22 shown in FIGS. 1 and 6. Since, in this case, thesecond DAC 21 is unnecessary and the speakers 23 can be also reduced innumber as compared with the number of speakers corresponding torespective multichannels, this leads to a reduction in the cost of thereceiver.

[0060] A fourth embodiment of the present invention will next bedescribed with reference to FIG. 7. In a manner similar to thedescription made up to now, the description of the already-describedelements will be omitted.

[0061] In FIG. 7, reference numerals 30, 31, 32, 33 and 40 indicate ananalog broadcasting antenna, an analog broadcasting tuner, an NTSCdecoder, an input processor and a selector, respectively. The analogbroadcasting antenna 30 and the analog broadcasting tuner 31 are onesused to receive the conventional analog broadcast. When a user selectsthe display of a video signal corresponding to the received analogbroadcast on a monitor 18, a system controller 7 is informed of itthrough the proper user interface (e.g., an unillustrated remotecontroller) and transfers it to required blocks. In the present mode,the analog broadcast signal received by the analog broadcasting antenna30 and frequency-converted by the analog broadcasting tuner 31 isconverted to component signals (separated into luminance andcolor-difference signals) by the NTSC decoder 32. The component signalspasses through a memory bus 10 and a memory interface 9 via the inputprocessor 33, selector 40 and reformatter 14 so as to be stored in amemory 8. Incidentally, as described in FIG. 4, a built-in VTR may beconfigured in which the driving circuit 17 and the monitor 18 shown inFIG. 7 are replaced with the output circuit 26 and the recording device27. Alternatively, an built-in DVD may be constructed in which the DAC16, driving circuit 17 and monitor 18 shown in FIG.. 7 are replaced bythe output circuit 26 and the recording device 27. These drawings areillustrated in FIGS. 14 and 15.

[0062]FIG. 8 is a block diagram showing the NTSC decoder 32 and theinput processor 33. In FIG. 8, reference numeral 321 indicates a combfilter, reference numeral 322 indicates a color decoder, referencenumeral 323 indicates a luminance signal delay circuit, referencenumeral 324 indicates a synchronizing separator circuit, referencenumerals 331, 332, 333 indicate first to third analog-digital converters(hereinafter described as “ADC”), reference numeral 334 indicates amultiplexer, reference numeral 335 indicates an analog clock generator,reference numeral 336 indicates an enable signal generator, andreference numeral 337 indicates an address generator, respectively.

[0063] An analog video signal inputted from the analog broadcastingtuner 31 corresponds to a composite signal obtained by combining theluminance signal and the two color-difference signals together inmultiplex form as is generally known. As the form of the compositesignal, there are known the NTSC system used in Japan and North America,the PAL system used in Europe (except for France) and the SECAM systemused in France and Russia. While the NTSC system has been described inthe present drawing, the present invention is not limited to the NTSCsystem. It is needless to say that the present invention can be appliedto the PAL and SECAM systems. The NTSC signal inputted from the analogbroadcasting tuner 31 is separated into luminance and color orchrominance signals by the comb filter 321. In response to thechrominance signals, the color decoder 322 produces two color-differencesignals called “(R-Y) and (B-Y)”, for example. On the other hand, theluminance signal is caused to coincide in delay time with the twocolor-difference signals by the luminance signal delay circuit 323.Further, the synchronizing separator circuit 324 detects horizontal andvertical synchronizing signals of the NTSC signal. Thesecolor-difference signals, luminance signal and horizontal and verticalsynchronizing signals are outputted to the input processor 33.

[0064] The analog clock generator 335 of the input processor 33 performsmultiplication on the horizontal synchronizing signal to generate aclock signal of 13.5 MHz, for example. The clock signal is supplied tothe three ADC 331 through 333 so that the color-difference and luminancesignals inputted to these ADC 331 through 333 are converted into digitaldata. The color-difference and luminance signals converted to thedigital data are supplied to the multiplexer 334. The input processor 33is also supplied with a digital clock generated from the clock generator6 of the decoder device. The digital clock is higher in frequency thanthe clock signal generated by the analog clock generator 335. Thedigital clock has a frequency of 54 MHz or 81 MHz, for example but isone synchronized with the pictorial data in the coded bit stream of thetransport stream. Further, the digital clock is not synchronized withthe clock signal generated from the analog clock generator 335. Thedigital clock is inputted to the multiplexer 334, enable signalgenerator 336 and address generator 337.

[0065] The enable signal generator 336 receives the clock signalgenerated from the analog clock generator 335 and thereby generates anenable signal with timing provided to allow the determination of digitaldata outputted from the three ADC 331 through 333 during one cycle ofthe digital clock. Described specifically, since 81 MHz is equal to sixtimes 13.5 MHz but is in asynchronism in frequency, the leading edges ofclocks at five to seven times in the digital clock are included in onecycle of 13.5 MHz. The enable signal indicates a data determinationperiod of one cycle of 81 MHz during one cycle of 13.5 MHz. Themultiplexer 334 captures the color-difference and luminance signalsconverted to the digital data with the digital clock, using the enablesignal and performs asynchronous-synchronous clock conversion on thesame. Further, the enable signal is supplied even to the address signalgenerator 337 from which an address signal corresponding to the positionon the screen, of the digital data multiplexed by the multiplexer 334 isgenerated and outputted. As a result, the analog broadcast signalasynchronized with the transport stream transmitted in digitalbroadcasting can be processed with the digital clock. While the inputprocessor 33 shown in FIG. 8 performs multiplexing with the digitalclock, there is also known a method of multiplexing some or all of theluminance and color-difference signals in a state of an analog signal,converting it into digital form and thereafter performingasynchronous-synchronous clock conversion to timing of the digitalclock.

[0066] Returning to the description of FIG. 7, the memory 8 selectsstoring pictorial data according to the selection as to whether an imageto be displayed on the monitor 18 is based on the digital broadcast oranalog broadcast. When it is based on the digital broadcast, itindicates pictorial data decoded by a video decoder 12. When it is basedon the analog broadcast, it corresponds to pictorial datadigitally-converted by the input processor 33. Theses are switched bythe selector 40, after which it is inputted to the reformatter 14 whereit is converted to an image or picture format suitable for the monitor18. The resultant data is displayed or projected onto the monitor 18through a second OSD circuit 15 and further the first DAC 16 and monitordriving circuit 17. When the pictorial data based on the analogbroadcast is displayed, the reading of the pictorial data from thememory 8 by the reformatter 14 is performed according to the digitalclock and carried out based on the horizontal and vertical synchronizingsignals produced with the digital clock. However, a series of operationsfor capturing motion picture data by the input processor 33 and writingthe data into and reading the data from the memory 8 by the reformatter14 implement a function as a frame synchronizer.

[0067] With respect to audio signals, an audio signal used in thedigital broadcast, which is obtained by decoding the input by the audiodecoder 20, and an audio signal used in the analog broadcast, which isobtained from the analog broadcasting tuner 31, are both supplied to aspeaker driving circuit 22 where either of them is selected according tothe choice of the pictorial data and the selected one sounds through aspeaker 23.

[0068] In the present embodiment described above, a receivercorresponding to the analog broadcast and the digital broadcast can beimplemented because the digital broadcast and the analog broadcast canbe projected onto the same monitor 18.

[0069] A fifth embodiment of the present invention will next bedescribed with reference to FIG. 9. The description of certain commonelements will be omitted in a manner similar to the description of theembodiments shown above up to now.

[0070] In FIG. 9, reference numeral 34 indicates a third reformatter andreference numeral 35 indicates a PinP mixer, respectively.

[0071] While an input processor 33 converts a video signal used in ananalog broadcast into digital form as described above, the outputthereof is supplied to the third reformatter 34. The third reformatter34 is also identical in configuration to that described in FIG. 2. Thethird reformatter 34 converts the video signal used in the analogbroadcast to an arbitrary picture format while using a memory 8, andoutputs the converted output to the PinP mixer 35. The presentembodiment is different from the fourth embodiment. The pictorial dataobtained by converting the video signal used in the analog broadcastinto digital form, and the pictorial data obtained by decoding the codedvideo stream used in the digital broadcast by the video decoder 12 areboth stored in the memory 8. A first reformatter 14 converts thepictorial data used in the digital broadcast into an arbitrary pictureformat using the memory 8. Further, the third reformatter 34 has theframe synchronize function of converting the pictorial data used in theanalog broadcast to horizontal and vertical synchronizing signalsidentical to the pictorial data used in the digital broadcast. These twopictorial data are combined into one by the PinP mixer 35. The combinedpictorial data is projected onto a monitor 18 through a first DAC 16 anda monitor driving circuit 17.

[0072] In the present embodiment as described above, the received imagesor pictures used in both the analog and digital broadcasts can bedisplayed simultaneously using a picture-in-picture display format.Described specifically, a window is provided at an arbitrary position ofa full-sized digital broadcast received image, and the analog broadcastreceived image reduced in size is put in the window. In contrast tothis, the digital broadcast received image and the analog broadcastreceived image are reversed, and two windows substantially identical insize are provided within a TV screen, whereby the digital broadcastreceived image and the analog broadcast received image can be projectedonto their windows.

[0073] As described in FIG. 4, a built-in VTR may be constructed inwhich the driving circuit 17 and monitor 18 shown in FIG. 9 are replacedwith an output circuit 26 and a recording device 27. Alternatively, abuilt-in DVD may be constructed in which the DAC 16, driving circuit 17and monitor 18 shown in FIG. 9 are replaced with an output circuit 26and a recording device 27. These drawings are shown in FIGS. 16 and 17.

[0074]FIG. 10 shows a sixth embodiment of the present invention. In thepresent embodiment, only the blocks employed in the embodimentsdescribed until now are utilized and no new ones are provided. If thepresent embodiment is compared with the fifth embodiment shown in FIG.9, then the second reformatter 24, third DAC 25, recording outputcircuit 26, recording device 27, downmixer 28 and fourth DAC 29described in the third embodiment of FIG. 6 are added thereto. Theseblocks are provided for recording of decoded motion picture dataavailable in the digital broadcast. The second reformatter 24 readsdecoded pictorial data used in the digital broadcast from a memory 8independently of a first reformatter 14 and a third reformatter 34 andconverts it to an image or picture format of SDTV for recording. As aresult, in the present embodiment, the decoded motion picture data usedin the digital broadcast can be recorded in the recording device 27regardless of whether pictorial data displayed on the monitor 18 isbased on the analog broadcast or the digital broadcast, or both arebased on a picture-in-picture format.

[0075] A seventh embodiment of the present invention will next bedescribed with reference to FIG. 11. If the present embodiment iscompared with the sixth embodiment shown in FIG. 10, a second analogbroadcasting antenna 36, a second analog broadcasting tuner 37, a secondNTSC decoder 38 and a second PinP mixer 39 are added to the presentembodiment.

[0076] In the present embodiment, the aforementioned analog broadcastingantenna 30, analog broadcasting tuner 31 and NTSC decoder 32 performfirst analog broadcasting reception, and the second analog broadcastingantenna 36, second analog broadcasting tuner 37 and second NTSC decoder38 perform second analog broadcasting reception simultaneously. Thesecond PinP mixer has memory means thereinside and synchronizes the tworeceived analog broadcasting pictorial data with each other to therebyobtain one synthesized analog broadcasting pictorial data in thepicture-in-picture format. The input processor 33 inputs the combinedanalog broadcasting pictorial data therein and performs the sameoperation as that in the sixth embodiment subsequently to this input.

[0077] Thus, in the present embodiment, the picture-in-picture betweenthe analog broadcasts can be also carried out as well as the combinationof the analog broadcast and the digital broadcast. If a tuner and adecoder used for the digital broadcast are prepared as another set andthey are replaced by the second analog broadcasting antenna 36, thesecond analog broadcasting tuner 37 and the second NTSC decoder 38, thenthe picture-in-picture between the digital broadcasts is also allowed.Even in these cases, the same display as the description of thepicture-in-picture in FIG. 9 can be done.

[0078] While we have shown and described several embodiments inaccordance with our invention, it should be understood that disclosedembodiments are susceptible of changes and modifications withoutdeparting from the scope of the invention. Therefor, we do not intendedto be bound by the details shown and described herein but indented tocover all such changes and modifications as fall within the ambit of theappended claims.

What is claimed is:
 1. A decoder device, comprising: a motion picturedata decoder which decodes digital motion picture data to thereby obtaindecoded motion picture data; a memory which stores the decoded motionpicture data therein; a first picture format converter which convertsthe decoded motion picture data into a picture format to thereby obtainfirst format-converted motion picture data; a second picture formatconverter which converts the decoded motion picture data into a pictureformat to thereby obtain second format-converted motion picture data;and an output device which outputs both the first format-convertedmotion picture data and the second format-converted motion picture datatherefrom.
 2. A decoder device according to claim 1, wherein the motionpicture data decoder includes a voice data decoder which decodesmultichannel voice data; and wherein the decoder device furthercomprises: a downmixer which downmixes the decoded multichannel voicedata decoded by the voice data decoder so as to reduce a number ofchannels thereof to thereby obtain downmixed voice data; an outputdevice which outputs the decoded multichannel voice data therefrom; andan output device which outputs the downmixed voice data therefrom.
 3. Adecoder device, comprising: a motion picture data decoder which decodesdigital motion picture data to thereby obtain decoded motion picturedata; a memory which stores the decoded motion picture data therein; afirst on-screen data multiplexer which mixes the decoded motion picturedata with first graphics data to thereby obtain first on-screendata-mixed motion picture data; a first picture format converter whichconverts the first on-screen data-mixed motion picture data into apicture format to thereby obtain first format-converted motion picturedata; a second on-screen data multiplexer which mixes the motion picturedata format-converted by the first picture format converting means withsecond graphics data to thereby obtain second on-screen data-mixedmotion picture data; a second picture format converter which convertsthe first on-screen data-mixed motion picture data into a picture formatto thereby obtain second format-converted motion picture data; an outputdevice which outputs the first format-converted motion picture datatherefrom; and an output device which outputs the secondformat-converted motion picture data therefrom.
 4. A decoder device,comprising: a motion picture data decoder which decodes digital motionpicture data to thereby obtain decoded motion picture data as firstmotion picture data; a memory which stores the decoded motion picturedata therein; a picture data capturing device which inputs second motionpicture data therein; a motion picture data storing device which enablesthe memory to store the second motion picture data therein; a pictureformat converter which converts each of the first motion picture dataand the second motion picture data into a picture format to therebyobtain format-converted motion picture data; and an output device whichoutputs the format-converted motion picture data therefrom.
 5. Areceiver, comprising: a motion picture data decoder which decodesdigital motion picture data to thereby obtain decoded motion picturedata as first motion picture data; a memory which stores the decodedmotion picture data therein; a picture data capturing device whichinputs second motion picture data therein; a motion picture data storingdevice which enables the memory to store the second motion picture datatherein; a picture format converter which converts each of the firstmotion picture data and the second motion picture data into a pictureformat to thereby obtain format-converted motion picture data; and adisplay which displays the format-converted motion picture data thereon.6. A decoder device, comprising: a motion picture data decoder whichdecodes digital motion picture data to thereby obtain decoded motionpicture data as first motion picture data; a memory which stores thedecoded motion picture data therein; a picture data capturing devicewhich inputs second motion picture data therein; a motion picture datastoring device which enables the memory to store the second motionpicture data therein; a first on-screen data multiplexer which mixes thefirst motion picture data with first graphics data to thereby obtainfirst on-screen data-mixed motion picture data; a picture formatconverter which converts each of the first on-screen data-mixed motionpicture data and the second motion picture data into a picture format tothereby obtain format-converted motion picture data; a second on-screendata multiplexer which mixes the format-converted motion picture datawith second graphics data to thereby obtain second on-screen data-mixedmotion picture data; and an output device which outputs the secondon-screen data-mixed motion picture data therefrom.
 7. A receiver,comprising: a motion picture data decoder which decodes digital motionpicture data to thereby obtain decoded motion picture data as firstmotion picture data; a memory which stores the decoded motion picturedata therein; a picture data capturing device which inputs second motionpicture data therein; a motion picture data storing device which enablesthe memory to store the second motion picture data therein; a firston-screen data multiplexer which mixes the first motion picture datawith first graphics data to thereby obtain first on-screen data-mixedmotion picture data; a picture format converter which converts each ofthe first on-screen data-mixed motion picture data and the second motionpicture data into a picture format to thereby obtain format-convertedmotion picture data; a second on-screen data multiplexer which mixes theformat-converted motion picture data with second graphics data tothereby obtain second on-screen data-mixed motion picture data; and adisplay which displays the second on-screen data-mixed motion picturedata thereon.
 8. A decoder device, comprising: a motion picture datadecoder which decodes digital motion picture data to thereby obtaindecoded motion picture data as first motion picture data; a memory whichstores the decoded motion picture data therein; a picture data capturingdevice which inputs second motion picture data therein; a motion picturedata storing device which enables the memory to store the second motionpicture data therein; a first picture format converter which convertsthe first motion picture data into a picture format to thereby obtainfirst format-converted motion picture data; a second picture formatconverter which converts the second motion picture data into a pictureformat to thereby obtain second format-converted motion picture data; apicture-in-picture mixer which mixes the first format-converted motionpicture data and the second format-converted motion picture datatogether to thereby obtain picture-in-picture motion picture data; andan output device which outputs the picture-in-picture motion picturedata.
 9. A receiver, comprising: a motion picture data decoder whichdecodes digital motion picture data to thereby obtain decoded motionpicture data as first motion picture data; a memory which stores thedecoded motion picture data therein; a picture data capturing devicewhich inputs second motion picture data therein; a motion picture datastoring device which enables the memory to store the second motionpicture data therein; a first picture format converter which convertsthe first motion picture data into a picture format to thereby obtainfirst format-converted motion picture data; a second picture formatconverter which converts the second motion picture data into a pictureformat to thereby obtain second format-converted motion picture data; apicture-in-picture mixer which mixes the first format-converted motionpicture data and the second format-converted motion picture datatogether to thereby obtain picture-in-picture motion picture data; and adisplay which displays the picture-in-picture motion picture data.
 10. Adecoder device, comprising: a motion picture data decoder which decodesdigital motion picture data to thereby obtain decoded motion picturedata as first motion picture data; a memory which stores the decodedmotion picture data therein; a picture data capturing device whichinputs second motion picture data therein; a motion picture data storingdevice which enables the memory to store the second motion picture datatherein; a first on-screen data multiplexer which mixes the first motionpicture data with first graphics data to thereby obtain first on-screendata-mixed motion picture data; a first picture format converter whichconverts the first on-screen data-mixed motion picture data into apicture format to thereby obtain first format-converted motion picturedata; a second picture format converter which converts the second motionpicture data into a picture format to thereby obtain secondformat-converted motion picture data; a picture-in-picture mixer whichmixes the first format-converted motion picture data and the secondformat-converted motion picture data together to thereby obtainpicture-in-picture motion picture data; a second on-screen datamultiplexer which mixes the picture-in-picture motion picture data withsecond graphics data to thereby obtain second on-screen data-mixedmotion picture data; and an output device which outputs the secondon-screen data-mixed motion picture data therefrom.
 11. A receiver,comprising: a motion picture data decoder which decodes digital motionpicture data to thereby obtain decoded motion picture data as firstmotion picture data; a memory which stores the decoded motion picturedata therein; a picture data capturing device which inputs second motionpicture data therein; a motion picture data storing device which enablesthe memory to store the second motion picture data therein; a firston-screen data multiplexer which mixes the first motion picture datawith first graphics data to thereby obtain first on-screen data-mixedmotion picture data; a first picture format converter which converts thefirst on-screen data-mixed motion picture data into a picture format tothereby obtain first format-converted motion picture data; a secondpicture format converter which converts the second motion picture datainto a picture format to thereby obtain second format-converted motionpicture data; a picture-in-picture mixer which mixes the firstformat-converted motion picture data and the second format-convertedmotion picture data together to thereby obtain picture-in-picture motionpicture data; a second on-screen data multiplexer which mixes thepicture-in-picture motion picture data with second graphics data tothereby obtain second on-screen data-mixed motion picture data; and adisplay which displays the second on-screen data-mixed motion picturedata thereon.
 12. A decoder device, comprising: a motion picture datadecoder which decodes digital motion picture data to thereby obtaindecoded motion picture data as first motion picture data; a memory whichstores the decoded motion picture data therein; a picture data capturingdevice which inputs second motion picture data therein; a motion picturedata storing device which enables the memory to store the second motionpicture data therein; a first picture format converter which convertseach of the first motion picture data and the second motion picture datainto a picture format to thereby obtain first format-converted motionpicture data; a second picture format converter which converts the firstmotion picture data into a picture format to thereby obtain secondformat-converted motion picture data; and an output device which outputsboth the first format-converted motion picture data and the secondformat-converted motion picture data therefrom.
 13. A decoder deviceaccording to claim 12, further comprising a motion picture datasynthesizer which synthesizes a plurality of motion picture data tothereby create synthesized motion picture data, and inputs thesynthesized motion picture data to the picture data capturing device asthe second motion picture data.
 14. A decoder device, comprising: amotion picture data decoder which decodes digital motion picture data tothereby obtain decoded motion picture data as first motion picture data;a memory which stores the decoded motion picture data therein; a picturedata capturing device which inputs second motion picture data therein; amotion picture data storing device which enables the memory to store thesecond motion picture data therein; a first picture format converterwhich converts the first motion picture data into a picture format tothereby obtain first format-converted motion picture data; a secondpicture format converter which converts the second motion picture datainto a picture format to thereby obtain second format-converted motionpicture data; a picture-in-picture mixer which mixes the firstformat-converted motion picture data and the second format-convertedmotion picture data together to thereby obtain picture-in-picture motionpicture data; a third picture format converter which converts the firstmotion picture data into a picture format to thereby obtain thirdformat-converted motion picture data; and an output device which outputsboth the picture-in-picture motion picture data and the thirdformat-converted motion picture data therefrom.
 15. A decoder deviceaccording to claim 14, further comprising a motion picture datasynthesizer which synthesizes a plurality of motion picture data tothereby create synthesized motion picture data, and inputs thesynthesized motion picture data to the picture data capturing device asthe second motion picture data.